Caledonia, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38 °F (low) to 57.5 °F (high). Annual precipitation averages 37.9 Inches. Caledonia is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.8 °F | 28.5 °F | 1.63 in. |
| February | 15.7 °F | 32.6 °F | 1.63 in. |
| March | 25.5 °F | 44.5 °F | 2.12 in. |
| April | 35.9 °F | 57.6 °F | 3.7 in. |
| May | 47.5 °F | 69.1 °F | 4.41 in. |
| June | 57.4 °F | 78.8 °F | 5.45 in. |
| July | 61.4 °F | 82.3 °F | 3.85 in. |
| August | 59.7 °F | 80.7 °F | 4.15 in. |
| September | 51.8 °F | 74.3 °F | 3.68 in. |
| October | 40.2 °F | 61.3 °F | 2.9 in. |
| November | 29.3 °F | 46.3 °F | 2.38 in. |
| December | 18.7 °F | 33.7 °F | 1.99 in. |
| Annual | 38 °F | 57.5 °F | 37.89 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |